A typical vehicle air bag module comprises a folded air bag disposed inside a container, and an inflator (or gas generator) connected with the container. The vehicle air bag module is normally assembled outside the vehicle, and loaded as a complete unit into the vehicle. At the onset of a collision, the inflator is actuated and rapidly discharges an inert, non-toxic gas (e.g., nitrogen). The gas is directed into the air bag, forces the air bag out of the container, and rapidly inflates the air bag to cushion a vehicle occupant against impact with a structural part of the vehicle.
It is well known to provide a relatively strong structural member (referred to herein as a "reaction device") as a part of the container. The reaction device may comprise a reaction can (see e.g., U.S. Pat. No. 4,842,300) or a reaction plate (see e.g., U.S. Pat. No. 4,915,410). Generally, the air bag and the inflator are anchored to the reaction device, and the reaction device is connected to a structural part of the vehicle. During deployment of an air bag, the reaction device takes up forces from the air bag and the inflator, and transmits at least part of those forces to the structural part of the vehicle. Thus, the inflator and the air bag remain anchored to the reaction device as the air bag is being deployed.
In the construction of an air bag module, it is desirable to make the module as compact as possible, to fit in the limited space available within a vehicle. For example, a driver side air bag module, which is designed to be incorporated into the steering wheel of a vehicle, must be particularly compact so as to fit the limited space available in the steering wheel. Further, there is a continuing need to provide air bag modules which are formed of relatively few parts, which are simple in construction, and economical and efficient to produce and assemble.